Depends on the TV and how experimental. If the TV is mid-60s on there are probably no common audio tubes within - before that you could find the 6_N7 serier and ofteh the 12A_7 series as well as 6BQ5 and 6GK5s. Also most used power trannies which may have strange voltages but can provide useful, if oversize, trannies - also losta resistors, non-electro caps, etc. and even tube sockets if you don't mine drilling them out (this was my first source of electronics parts). Now if you are willing to work less familiar, non-boring, tubes there are scads that are useful. Any output tube - horizontal, vertical, video - can be used to drive audio you just might have trouble finding a tranny. And there are usually lots of triode/pentode combination tubes.